Shaft coupling



May 8 1951 J. w. Gor-'F 2,551,735

SHAFT COUPLING Filed April 25, 1945 INvlN-I-UR:

- or end members I 4 and I5.

Patented May 8, 1951 SHAFT COUPLING James W. Go, Taunton, Mass.,assigner to Industrial Machine Works, Inc., South Hanson, Mass., acorporation of Massachusetts Application April 25, 1945, Serial No.590,262

6 Claims.` (Cl. 64-31) This invention relates particularly, although notexclusively, to shaft couplings for use in conapparatus as submarinedetecting devices, radio antennae (radar), etc. A shaft couplingsuitable for use in such relationship must fulfill certain essentialrequirements, namely: it must permit of considerable variation in theaxial alinement (both lateral and angular) of the shafts connected; itmust be silent in its operation; and it must be free of all possibilityof lost motion or backlash, whether initial or as the result of wear,not only to prevent noise, but also to insure the accuracy of theangular positioning of the parts controlled. So far as I am aware, noshaft coupling heretofore devised has been capable of satisfactorilymeeting all of these requirements. In accordance with my invention thereis provided a coupling which permits a wide Variation, both lateral andangular (particularly the latter) in the shaft axes; which is noiselessin its operation; and which can be maintained entirely free of lostmotion or backlash.

The invention will best be understood from the following description ofcertain forms or embodiments thereof illustrated in the accompanyingdrawings, these, however, having been chosen for purposes ofexemplication merely, as it is contemplated that the invention, asdei-ined by the claims hereunto appended, may be otherwise embodiedwithout departure from the spirit and scope thereof.

In said drawings:

Fig. l is a longitudinal section of a coupling embodying a simple formof the invention, showing the shaft axes in substantial alinement.

Fig. 2 is a similar view showing the shaft axes angularly disposed.

Figs. 3 and 4 are elevations, as viewed from directions at right anglesto one another, of a modified construction.

Fig. 5 is a an elevation, partly in longitudinal section, of a furthermodication.

Fig. 6 is a cross section taken substantially on the line 6 6, Fig. 5.

Referring to Figs. l and 2, two shafts to be coupled are indicated at i0and It. Secured to the adjacent ends of the shafts Il and II,respectively, as by keys I2 and set screws. I3, are heads Interposedbetween the end members I 4 and I5 is a floating intermediate member I6.The end and intermediate members are formed with interengaging ribs andgrooves Il, I8, I'Ia, Ia of which those at the opposite sides of theintermediate member, respectively, are disposed transverse (preferablyat right angles) to one another; that is to say, the ribs Il' andgrooves I8 connecting the intermediate member with the end member I 4are substantially perpendicular to the ribs Ila and grooves Itaconnecting said intermediate member with the end member I5.

As thus far described, the coupling is of the well-known @ldham type,which permits lateral offsetting cf the shaft axes while maintaining thedriving connection, but, in accordance with the present invention, theribs I I, Ha and grooves I8, Ita are in the form, or have the profiles,of intermeshing (preferably involute) gear teeth having rolling contactwith engaging surfaces only at their lateral faces, as indicated at a,and clearances, indicated at b, between the outer ends of the ribs andthe bottoms of the grooves. Also, in accordance with the invention, theintermediate member I5 is composed of a sintered pulverized bearingmetal, commonly used in bearing bushings and the like, providing anelement capable of absorbing and retaining a considerable quantity ofiiuid lubricant. Further, in accordance with the invention, the faces ofthe end members I 4 and I5 are of substantially cylindrical form, thatis to say, are curved about axes parallel respectively to the ribs andgrooves at the corresponding side of the intermediate member i6 andconsequently transverse to one another, so that the curvatures of thefaces of the respective members are in transverse planes. Thus. as shownin Fig. l, the face 20 of the end member Ill lies in a cylindricalsurface cywhose axis of curvature d is parallel to the rib Il and grooveI3, and it will be understood that the face 20a,

Y of the member I5 is similarly curved about an axis parallel to the ribIla and groove I8a.

By forming the interengaging ribs and grooves in the shape ofintermeshing, rolling contact gear teeth, as described, severalimportant advantages are achieved. Since the engagement of the parts isonly along their lateral faces a, with clearances b at the bases, anytendency to lost motion or blacklash can, at any time, be taken up andeliminated by loosening one of the set screws I3 and axially adjustingthe corresponding end member in the direction toward the intermediatemember and other end member. The rolling contact gear tooth formation,in connection with the relatively transversely curved formation of theend member faces 2! and v20a about axes parallel to the ribs II and Ila,respectively, permits a considerable "angular variation of the shaftaxes without looseness or noise, the parts merely rolling upon oneanother in the manner of intermeshing gears, this action beingsubstantially contributed to by the self-lubricating character of theintermediate member I6.

As shown in Figs. 1 and 2, each end member is formed with a single ribI1, I'Ia (although each of these comprises two alined sections separatedby an axial bore 2|, 2|a) each cooperating with (in substance) a singlegroove I8, I8a in the intermediate member. While such a constructionillustrates the major features of the invention, and is suitable for usein certain situations, the preferred construction shown in Figs. 3 and 4utilizes the rolling gear principle to a more complete extent, providesfor a somewhat wider variation in the angular position of the shaftaxis, and also affords a firmer and more positive connection of theparts in all positions. As shown in Figs. 3 and 4, each of the endmembers |40, I50 (which may be secured to their respective shaftsections as in Figs. 1 and 2) is connected with the intermediate member|60 by a plurality of parallel interengaging ribs |10, IIa and grooves|80, I80a all in the form of rolling contact, intermeshing gear teethsubstantially as above described in connection with the gear tooth ribsand grooves l1, I8, I'Ia, Ia. One set of ribs at each side of theintermediate member |60 terminates in a curved surface having an axis ofcurvature parallel to the corresponding ribs. Thus, by comparing Figs. 3and 4, it will be seen that the ribs I'I0 on the end member |40terminate in a cylindrical surface c' whose axis al is parallel to saidribs |10, while the ribs IIa on the end memberv |50 terminate in acylindrical surface c2 whose axis d2 is parallel to said ribs I'I0a andconsequently transverse to the axis d.

As above explained in connection with Figs. l and 2, any looseness orbacklash which may develop as the result of wear of the gear toothsurfaces can be taken up by axial adjustment of one or the other or bothof the end members. In Figs. 5 and 6 is shown a construction wherein anyincipient looseness due to wear is immediately and automatically takenup, and thereby prevented, without attention on the part of theoperator. In Figs. 5 and 6, the end members I4I and I5I and intermediatemember IGI are substantially identical with the corresponding members inFigs. 3 and 4, except that the end member I4I is not fixed to its shaftsection I0 I, but is mounted thereon with a sliding t. Fixed to theshaft section |0I, as by a set screw I3I, is a collar 22 carryinglongitudinally extending guide pins 23 which are received in openings 24in the end member I4! and thereby hold said end member against rotationwith respect to the shaft while guiding the same for axial movementthereon. Interposed between the collar 22 and end member I4I are springs25 having their ends housed in suitable sockets formed in said parts.The springs 25 act at all times to yieldingly urge the end member I4 Iaxially toward the intermediate member I6I and end member I5|, therebymaintaining the several sets of cooperating gear tooth ribs and groovesin close engagement at all times.

It will be observed that a coupling in accordance with the invention canbe produced at very low cost as compared to its quality of operation andadvantageous results, since the intermediate members can be readilyproduced, in quantities, in a suitably designed die, while the parallelgear tooth ribs and grooves on the end members can be formed by a simplebreaching operation.

I claim:

1. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member, said end and intermediate members havinginterengaging ribs and grooves of which those at the opposite side ofthe intermediate member, respectively, are disposed transverse to oneanother, said ribs and grooves being in the form of gear teeth havingrolling contact with engaging surfaces only at their lateral faces andclearances between the outer ends of the ribs and the bottoms of thegrooves.

2. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member, said end and intermediate members having, on eachside of said intermediate member, a plurality of parallel interengagingribs and grooves of which those at the opposite sides of theintermediate member, respectively, are disposed transverse to oneanother, said ribs and grooves being in the form of gear teeth havingrolling contact with engaging surfaces only at their lateral faces andclearances between the outer ends of the ribs and the bottoms of thegrooves.

3. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member composed of a sintered pulverized bearing metal,said end and intermediate members having, on each side of saidintermediate member, a plurality of interengaging ribs and grooves ofwhich those at the opposite side of the intermediate member,respectively, are disposed transverse to one another, said ribs andgrooves being in the form of gear teeth having rolling contact withengaging surfaces only at their lateral faces and clearances between theouter ends of the ribs and the bottoms of the grooves.

4. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member, said end and intermediate members havinginterengaging ribs and grooves of which those at the opposite side ofthe intermediate member, respectively, are disposed transverse to oneanother, said ribs and grooves being in the form of gear teeth havingrolling contact with engaging surfaces only at their lateral faces andclearances between the outer ends of the ribs and the bottoms of thegrooves, the adjacent faces of the intermediate member and therespective end members being relatively curved respectively about axesdisposed transverse to one another.

5. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member, said end and intermediate members havinginterengaging ribs and grooves of which those at the opposite side ofthe intermediate member, respectively, are disposed transverse to oneanother, said ribs and grooves `being in the form of gear teeth havingrolling contact with engaging surfaces only at their lateral faces andclearances between the outer ends of the ribs and the bottoms of thegrooves, the adjacent faces of the intermediate member and therespective end members being relatively curved about axes parallel tothe ribs and grooves thereon, respectively.

6. A shaft coupling comprising heads or end members for attachment tothe adjacent ends of the shaft sections to be coupled and an interposedintermediate member, said end and intermediate members having on eachside of said Yintermediate member, a plurality of parallel in- 6REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 481,780 Brown Aug. 30, 18921,244,533 Morse Oct. 30, 1917 1,407,445 Spangler Feb. 21, 1922 1,702,407Lyman Feb. 19, 1929 2,011,147 Haselau Aug. 13, 1935

